I believe that yetis have the power to alter our memories. At one point humans knew about the yeti, but as the yetis’ psychic powers grew, they forced us to forget them… just as they usually make us forget that we’ve seen them today. Ontogeny recapitulates phylogeny. I don’t have any proof of this, but I get very strong impressions. I believe the yetis are planting these thoughts in my mind.